This invention relates to an improved bullet trap.
Conventional bullet traps are generally of one of four designs: a sand bunker, a convergent impact plate, a water chamber or a flowing water tube. Sand bunker and convergent impact plate traps require a considerable amount of maintenance and do not have any inherent means to indicate a failure (penetration) of the trap other than by visual inspection. Penetration of the trap can result in further projectiles being fired into unintended areas, causing further facility damage and potential risk of injury to personnel if the failure is undetected even for a short period of time. This is particularly true in situations requiring fixed mount weapon firing of relatively large amounts of ammunition. Conventional water chamber traps such as that of U.S. Pat. No. 2,812,660, issued Nov. 12, 1957 to N. D. Marden et al, are not suitable where horizontal firing is needed since such conventional water chamber traps require that the bullet be shot downwardly into the water. Conventional water chamber traps such as that of U.S. Pat. No. 2,420,304, issued May 13, 1947 to D. T. Diem, or U.S. Pat. No. 3,447,806, issued June 3, 1969 to H. Pfaff et al, which have a downwardly rearwardly inclined armored deflection plate above a water chamber do not indicate failures of the impact plate. Sand bunker type bullet traps require daily attention to the raking out of larger projectile masses and to adjust the sand slope. Regular replacement of the sand is required as the sand becomes pulverized through repeated bullet impact and raking. Disposal of the spent sand is difficult and expensive as it must be treated as a hazardous waste due to its lead content. Conventional convergent impact plate traps such as that of U.S. Pat. No. 3,701,532, issued Oct. 31, 1972 to Nikoden et al, require the handling of very heavy armor plate sections to replace worn pieces periodically and do not have any indication of failure of the deflection plate. This work is difficult to accomplish in a confined ballistic range and it requires special equipment for lifting with considerable time and expense. Lead dust generated during use of a convergent impact plate bullet trap requires elaborate ventilation systems with bag house lead dust filtration and recovery or employee respiratory protective equipment. Conventional flowing water tube type bullet traps such as that of U.S. Pat. No. 2,356,992, issued Aug. 29, 1944 to I. R. Gilson, or U.S. Pat No. 3,217,534, issued Nov. 16, 1965 to C. T. Bingham et al, utilize complex piping, pumping equipment, and require power for running pumps, and do not provide failure indication to an operator. There is need for a bullet trap which solves the above problem with existing designs.
It is an object of this invention to provide a bullet trap which gives an indication when a failure occurs.
It is a further object of this invention to provide a bullet trap which requires relatively low maintenance.
It is a further object of this invention to provide a bullet trap which has a relatively low level of lead dust.
The present invention achieves these objects by providing a bullet trap which has an upper water chamber and a lower water chamber separated by an inclined impact plate and an air space. The trap is designed such that the bullet enters the trap and passes through the air space to impact upon the lower surface of the impact plate and fall into the lower water chamber. In the event that the bullet penetrates the impact plate, the bullet would be slowed or stopped by the upper water chamber and the water from the upper water chamber would leak into the lower water chamber to provide an indication of such penetration. The lower water chamber provides for lead dust control and relatively easy separation of the spent bullets of the energy absorbing media, in this case water, and thus eliminates personnel lead dust exposure and sharply reduces the quantity of waste material. The splashing action of the lower water chamber as the lower water chamber receives a bullet cools the impact area of the impact plate to extend plate life, particularly in cases involving automatic gun fire, thus further reducing the maintenance requirements. The trap can be of relatively simple construction and reduced cost compared to any conventional traps. The trap, in a further embodiment, has a flexibly mounted impact plate so that the plate can recoil to absorb bullet energy and thus reduce likelihood of penetration of the plate. Preferably, the plate is rotatably mounted to reduce the angle of bullet incidence upon bullet impact.